I dunno, in my 'here's your class date' packet, it quite clearly said that all new hires must now have a yellow fever vaccine before starting training. They provided an email address if you wanted to request an exemption, but also stated that you can't start until the exemption process is complete, and that sounded like it could be quite a delay.

So I got mine yesterday.

Hopefully I won't turn yellow. Or feverish.